Laboratory jack



FIG. 1 is a top plan view of a laboratory jack of the invention;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is one side elevational view thereof, the other side being a mirror image;

FIG. 6 is a top plan view of the laboratory jack of the invention in the expanded position;

FIG. 7 is a front elevational view thereof;

FIG. 8 is a rear elevational view thereof;

FIG. 9 is a bottom plan view thereof; and,

FIG. 10 is one side elevational view, the other being a mirror image.

The broken line showing some elements in the figures is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a laboratory jack, as shown and described. 